In Shoot 'Em Up, Clive Owen plays a man named Smith who never, ever stops firing his guns. He fires them two at a time, leaping across rooms blam! blam! blam! in glorious slow motion. He fires them in the middle of the sky, after plunging out of a plane without a parachute. He blasts away at an overly coiffed hairdo (''That ponytail doesn't make you look young, hip, or cool!''), at an umbilical cord that needs severing, at a team of assassins who burst into the room where he's making love an activity he keeps on doing the entire time that he's shooting.
Smith, in other words, does exactly what you'd expect the hero of a bloody, trashy, volcanically depraved action movie to do. He just does it a little bit...more so, and that's the rollicking good joke of Shoot 'Em Up, which has the inspiration to send up over-the-top action movies from Tango & Cashto Die Hard by nudging their slam-bang kinetic overkill right to the breaking point but not past it. Michael Davis, the writer-director of Shoot 'Em Up, recognizes that the action genre long ago devolved into knowing self-parody. The signature taglines, the nonchalant perfection of the heroes' bullet-blasting moxie all of this is so stylized it's already a joke. Clive Owen plays Smith as the classic megaplex loner-nihilist, a Bogart-meets-Bruce Willis with a heart of gold, and he does it absolutely straight, which is really the ultimate wink.
Smith's ''lovable'' trademark is chewing on carrots, like a film-noir Bugs Bunny. (He also uses them as weapons.) He teams up with a hooker (Monica Bellucci) who helps him to save an orphaned infant a nod to John Woo's great Hard-Boiled. Paul Giamatti, as the villain, has just the right feral sadistic sweatiness, and he does great, exasperated takes on the words ''God damn it!'' Shoot 'Em Up isn't out to be the Airplane! of ballistic blowouts (e.g., National Lampoon's Loaded Weapon 1). In two scenes out of three, it could just about pass for the thing it's satirizing. But then its pulpy violent excess will tip over...into slightly more excessive excess. That's its silly, scuzzball joy.